Timer making my application [ Not Responding]

i am using Windows.Forms.Timer

it is usually Making my Application Not Responding as my frequent interval is10seconds  after  every 10secs i am making a request to web service which is returning me json data and i am  making manipulation according to it.

so whenever there is new request in 10 secs my Windows Applications becomes Not Responding for that time interval

is there a way i can stop doing that.

Using

Windows Based Application C# 4.0

i had already made sure that when ever the interval is called time.stop is called and when all the manipulation is done timer.start() again

but this is not helping me.

Thanx